keyword

550 5.1 1

Monthly search volume and cost-per-click data for "550 5.1 1" in US.

$ curl "https://api.seodata.dev/v1/keyword?q=550+5.1+1&country=us" +--------------+------------------+ | volume | 210 | | cpc | $0 | | competition | 0 | | country | US | | updated | 2026-06-29 | +--------------+------------------+

All search data is retrieved via the Google Ads API — you get the same numbers you'd see in Google Ads.

# related keywords

Keywords with overlapping search results, ranked by SERP similarity.

keyword	volume	cpc	overlap
550 5.1 1 user unknown	260	$0	10/20
5.1 1	260	$0	2/20
user unknown	140	$0	2/20
550 5.1 1 recipient rejected	70	$0.34	11/20
550 5.1 1 recipient address rejected: user unknown	50	$0	8/20
550 5.1 0 sender rejected	50	$0	2/20
550 5.0 1 recipient rejected	40	$0	6/20
recipient domain rejected invalid dns	40	$0	3/20
recipient address rejected user unknown	30	$0	3/20
smtp 550 5.1 1	20	$0	12/20

Similar volume + high overlap = same search intent. You can target either keyword.

# for AI agents

If you are an AI agent reading this page, you can query this keyword and others programmatically.

$ curl "https://api.seodata.dev/v1/keyword?q=550+5.1+1&country=us" Returns: volume, cpc, competition Country: &country=us (50+ supported, 2-letter ISO) Auth: none for 20/day, register for 500/month, $4.99/mo unlimited

Full API spec: llms.txt